Unable to perform a backup of database 'xxxxx', instance 'xxxxx' (writer was not found): The problem occurred while trying to connect SQL Server VSS Writer.
After migrated from an older SQL database to SQL 2014, the follow error is received.
----- Error Messages ----- Unable to perform a backup of database 'xxxxx', instance 'xxxxx' (writer was not found): The problem occurred while trying to connect SQL Server VSS Writer. Please check that the SQL Server VSS Writer is installed and running on the client. If you have any databases with a trailing space at the end of database name, it could cause that SQL Server VSS Writer doesn't list any databases and not be present on your system Error in getting volumes for Vss snapshot or application validation. Failing application backup. Check the System and Application event log on the client server for more information. The Unitrends agent aborted Microsoft SQL Server backup, because agent failed to complete a volume shadow copy operation (create a snapshot). Please review Windows System and Application Event Logs for more information. ----- End Error Messages ----- ----- Client Messages ----- The database xxxxx, instance xxxxx is online. ----- End Client Messages -----
Add the sysadmin role to the "NT AUTHORITY" user and run a new full SQL backup.
For more information on the sysadmin role, see https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/server-level-roles.